Fuel pump



Dec.16, l1941.` c, H, BoUvY FUEL PUMP Filed April e, i959 2 Sheets-Sheet1 l IMI Tm/afar una Derc. 16, 1941. c. H. BoUvY 2,266,585

FUEL PUMP A Filed Apri] 6, 1959 2 Sheets-SheefI 2 NVENTOR.

f/5M #15mg BY 75W @uw @QMMWYMQ ATTORNEYs Patented Dec. 16, 1941 fUNITEDY STATES PATENT OFFICE FUEL PUMP Christiaan H. Bouvy, Detroit,Mich.

Application April 6, 1939, Serial N0. 266,257

(Cl. 10B-152) 6 Claims.

This invention relates to a fuel pump and has particularly to do with afuel pump for internal combustion engines.

In the past it has been common to provide vacuum operated fuel pumps inwhich two pumping members are interconnected and it has been common toprovide snap action connections between the control valves and thepumping members to control pressure or vacuum to the pumping members.The present invention contemplates a fuel pump which is self-containedin that no mechanical connection -is necessary between the pump and anoperating part of the engine. The pump of the present invention is to beoperated by differential pressures, one of the pressures beingatmospheric and the other being sub-atmospheric. However, if founddesirable the range of the pressure differential can be changed, onepressure being atmospheric and the other above atmospheric.

A further object of the invention has 1to do with provision of a pumpwhich will furnish a supply of fuel to an engine, as required at alimited maximum pressure. An additional object has to do with theprovision of a fuel pump in which the two pumping elements operateindependently of .each other as far as mechanical connection isconcerned.

It is a further object of the invention to provide a fluid-operated fuelpump with a simplified valve structure. The vacuumA operated pump hasthe advantage that it can be mounted outside of the engine compartmentin a cool location so as to avoid trouble from vapor locking. Also, thefeed line to the fuel pump, which is under sub-atmospheric pressure, isnot exposed to the heat in the engine compartment, as is the case with amechanical operated pump mounted on the engine.

Other features and objects of the invention having to do with details ofconstruction and operation, as, for example, the arrangement of ports inthe valve-cylinder structure, will be further brought out in thefollowing description and claims.

In the drawings:

Fig. 1 is a horizontal longitudinal section taken through a fuel pumpconstructed in accordance with the present invention.

Fig. 2 is a vertical section of the invention Y taken on lines 2--2 ofFig. 1. Section lines I-I of Fig. 2 refers to the section of Fig. 1.

Fig. 3 is a transverse section taken on the lines 3-3 of Fig. 2.

Fig. 4 is a diagrammatic presentation of the pump for purposes ofillustration, each of the passageways shown in the plane of the section.

Referring to Fig. 4, a fue] pump is showngenerally at 5 and consists oftwo housings 6 and 1 connected by a valve housing 8. Each ofthe housingsv6 and I is divided into two compartments by diaphragms 9 and III,respectively. To the Vleft of the diaphragm 9 and to the right of thediaphragm I are fuel pumping chambers and I2, respectively. To the rightofv the diaphragm 9 and to the left of diaphragm 0 are actuating orvacuum chambers |3 and I4.

A fuel tank I is connected to pumping chamber II through pipe I6 andcheck valve |'I and to pumping chamber I2 through pipe I8 and checkvalve I9. A carburetor is connected to pumping chamber |I through pipe2| and check valve 22 and to chamber I2 through pipe 23 and check valve24. Stops 25 are provided in chambers and I2 to limit the outwardmoveme'nt of the diaphragms. Springs 26 and 2'I are provided in chambersI3 and I4, respectively, and these springs tend to urge the diaphragms 9and lllvtoward .the stops 25.

The valve housing 8 vis provided with axialQ cylinder openings land 3|,.these cylinders being separated by a wall 32. vPortopenings 33a and 33hin cylinders 30 and 3|, respectively, open into a passageway 33connected via passageway 34 to a sourceof vacuum. Port openings 35a and35h in cylinders 30 and 3|, respectively, open into y a passageway 35connected via passageway 36 to the' atmosphere. Fig. 4 shows that Vacuumport y 33h in cylinder 3| is located to the left of the a atmosphericport 35h in cylinder 3|, while vacuum port33a in cylinder 30 is alsolocated to This non-symmetrical arrangement of ports is necessary `forproper operation.

Arport 3'I is formed in the wail of` cylinder 3|! and is connected by apassageway 38 to chamber I3. A similar Dort 39 is formed in the wall ofthe cylinder 3| and is connected to the chamber I4 by a passageway 4U.The axialwidth of Y ports 31 and 39 is equal to the axial distancebetween the inner edge of vacuum port 33a and the outer edge ofatmospheric port 35a, and also equal to the axial distance between theouter edge each provided with annular grooves 43 and 44. A suitablegroove is also provided in the piston for packing to provide forfrictonal contact between piston and cylinder. Connected to eachdiaphragm 9 and I8 are rods 45 and 46, respectively. Each of these rodsis provided with spaced collars 41 and 48. The portion of the rods 45and 46 between the collars 41 and 48 is passed through an axial opening49 in each of the pistons 38 and 3I, this opening being smaller than thecollars 41 and 48. The inner ends of the pistons 38 and 3I are alsoprovided with recesses in which the collars 41 may slide. It will beseen that the space between the collars 41 and 48 is greater than thelength of the opening 49 so that there will be a-lost motion betweenmovement of the rods and the pistons.

Referring now to the operation of the pump as shown in Fig. 4 thediaphragm I8 has just completed a discharge pumping stroke and isconnected to the atmosphere through passageways 36 and 35, port 35h,groove 44, port 39 and passageway 40. The diaphragm 9 has just completedan intake pumping stroke to the right and is now connected to theatmosphere through passageways 36 and 35, port 35a, groove 43, port 31and passageway 38. With the diaphragms in these positions, the fuelpumping chamber I2 has been ensmalled and the fuel pumping chamber I Ihas been enlarged and lled with fuel from the tank I5. diaphragm 9, willtend to ensmall the pumping chamber II, forcing the fuel through thecheck valve 22 and to the carburetor 28 through the pipe 2I During therst stages of the movement of the diaphragm'S to the left, the piston 42will remain in the position shown. VWhen the collar 41 on rod 45contacts the shoulder at the end of the opening 49 of piston 42, thepiston will start moving to the left with the diaphragm 9. When thepiston 42 is moved to the left a predetermined amount, the groove 44 inthe piston will rst be cut oil from port 35hl and atmospheric passageway35 and then be connected to port 33h and to the passageway 33 in thevalve housing, The passageway 33 is connected to subatmospheric pressureconduit 34 and 4consequently the actuating chamber I4 will be connectedto sub-atmospheric pressure through passageway 34, passageway 33, port33h, groove 44, port 39 and passageway 40. At this time lthe diaphragmI8 will start to move to the left in its intake stroke. Because of thelost motion between the collar 48 on rod 46 and the piston 4| there willbe no movement of the piston 4I during the first stages of the movementof the diaphragm I8.

VAfter about half the stroke of the diaphragm is completed, the collar48 will contact the piston 4I and move the same to the left therebycutting off the chamber I3 from atmospheric port 35a and passageway 35,and as the piston 4I reaches the end of its leftward movement, the

chamber I3 will be connected to sub-atmospheric pressure throughpassageways 34 and 33, vacuum port 33a, groove 43, port 31, andpassageway 38. 'I'his will initiate the intake stroke of diaphragm 9.Chamber II will again be illled with fuel through pipe I6 and checkvalve I1 and the diaphragm I8 will then move to the right by the actionof the spring 21 and will discharge fuel through the valve 24 to thecarburetor. It will be seen that if the need for fuel to the carburetoris discontinued, the pump will cease its operation until demand isre-established, in which'c'ase, either spring 26 or 21 may force itsrespective The spring 26, operating on thel diaphragm outward againstthe reduced fuel pressure in the discharge line feeding the carburetor.At this time the pump will again start to operate.

It is at the end of the discharge pumping stroke of diaphragm 9 that theactuating chamber I4 is connected to sub-atmospheric pressure and it isat the end of the intake stroke of diaphragm I8 that actuating chamberI3 is connected to sub-atmospheric pressure.l Similarly, at the end ofthe intake stroke of diaphragm 9, the chamber I4 is connected toatmospheric pressure and at the end of the discharge pumping stroke ofdiaphragm I8 the chamber I3 is connected to atmospheric pressure.

Referring now to the embodiment of the invention shown in Figs. 1, 2 and3, reference characters from Fig. 4 have been applied torFigs. 1, 2 and3 where they identify similar parts. The housing for the fuel pump inFigs. 1 and 2 is made up of a central housing 58 and two end housings 5Iand 52 bolted appropriately to the center housing with diaphragms 9 andI8 interposed. Each of the housings 5I and 52 are provided with endchambers 53' and 54 respectively with suitable bail means 55 for holdingthe same in position. The end housing 5I is provided with an entranceport 56 leading to the housing 53. A filter screen 51 separates the endchamber 53 from entrance valves 58 and 59, and chamber 53 serves assediment chamber. These valves are check valves of common construction.The valve 58 gives one way connection to chamber I2 and the valve 59gives vone way connection to chamber II through passageway 68 in thehousings 5I, 58 and 52. The chamber 54 which serves as an airdome toreduce pressure uctuations, is connected to the carburetor through aport 6I. A check valve 62 gives a one way connection from the chamber IIto the chamber 54 and the check valve 63 gives a one way connection fromchamber I2 to chamber 54 through a passageway 64 inhousings 52, 58 and5I. The embodiment of the pump shown in Figs. 1 and 2 is mounted inoperation so that the sediment chamber 53 is at the bottom and theairdome chamber 54 is at the top. Diaphragms 9 and I8 are clampedbetween reinforcing discs 65 and 66 which can serve also as stop membersby contacting the housings at the ends of the stroke of y the diaphragm.

This sleeve 61 has twov cylinders 38a and :HaV

formed in each end and separated by the wall 32. These lcylinders whichcorrespond to cylinders 38 and 3I of Fig. 4, are connected by the ports33a and 33h and passageway 33 which is open to the suction orsub-atmospheric passage 34. Passageway 35 also connectsv the atmosphericports 35a andy 35b in the cylinder walls and is open to the atmosphericpassage 36. Passageways 33 and 35, each in the form of an axial grooveon the outside of the sleeve 61are diametrically positioned, as shownparticularly in Figs. 2 and 3. In Fig. l the -ports 31 and 39 and thepassageways 38 and 48, formed as axial grooves in sleeve 61, are showndiametrically positioned in the sleeve 61, the passageway 38 leading tochamber I3 and the passageway 48 leading to chamber I4. Within thecylinders of sleeve 61 are pistons 4Ia and 42a each provided withgrooves 43 and 44 respectively,

.as described in connection with Fig. 4. Rods 68 and 69 are attached tothe diaphragms 9 and4 I8 respectively, which are clamped between thediscs B and 66, and each rod is provided with a portion having a reduceddiameter at its inner end to be received within an opening of thepistons #Ia and 42a. There is a lost motion connection between thepistons and rods as previously described. The operation of theembodiment of the invention shown in Figs. 1, 2 and 3 is identical withthat described in Fig. 4 and will not be repeated in detail.

As shown in Figs. l and 2, the chambers I3 and I4 are connected toatmosphere and the diaphragm 9 is ready to start a discharge pumping 33hso that the source of sub-atmospheric pres-` sgre Will be connected tochamber I4 throughpasasgeway 40, port 39, groove 44, port 3317 andpassageway 33. Similarly, when the diaphragm I0 has been moved to theright by differential pressures a predetermined distance, the piston 4Iawill then be shifted to the right to disconnect the chamber I3 from theatmospheric port and later be connected to the sub-atmospheric pressurethrough the passageway 38, port 31, groove 43, port 33a and pasasgeway33. This will cause movement of the diaphragm 9 to the left and thechamber I4 will then be again connected to atmosphere as shown.

It is, of course, within the contemplation of the invention that apressure above atmospheric be used in actuating chambers I3 and III. Insuch cases, a means equivalent to springs 26 and 21 should be providedto urge the diaphragms in a direction opposite to that in which they arenow urged by the springs.

What I claim is:

1. In a liquid fuel pump, opposed coaxial chambers, pumping elements insaid chambers to divide each chamber into a fuel pumping chamber and-.anactuating chamber, means urging said pumping elements in a direction toensmall said fuel pumping chambers, a central valve housing positionedbetween said pumping chambers, coaxial cylindrical recesses in saidvalve housing, valve members in said recesses, means connecting saidvalve members respectively to said pumping elements, an atmosphericpassageway connecting said valve recesses, a sub-atmospheric passagewayconnecting said valve recesses, passageways connecting each of saidactuating chambers with one of said valve recesses, said valve membersbeing arranged to be shifted to connect respectively said atmosphericand subatmospheric passageways with said actuating chambers, the valvemember connected to one pumping element being adapted to control theconnection of pressure to the actuating chamber of the other pumpingelement.

2. In a liquid fuel pump, opposed coaxial chambers, pumping elements insaid chambers to divide each chamber into a fuel pumping cham'- ber andan actuating chamber, means urging said pumping elements in a directionto ensmall said fuel pumping chambers, a central valve housingpositioned between said pumping chambers, coaxial cylindrical recessesin said valve housing, valve members in said recesses, means forming alost motion connection between said valve members respectively and saidpumping elements, atmospheric passageway connecting said valve recesses,a sub-atmospheric passageway connecting said valve recesses, passagewaysconnecting each of said actuating chambers with one of said valverecesses, said valve members being arranged to be shifted to connectrespectively said atmospheric and sub-atmospheric passageways with' saidactuating chambers, the valve member connected to one pumping elementbeing adapted to control the connection of pressure to the actuatingchamber of the other pumping element.

3. In a liquid fuel pump, a central housing having inlet and outletopenings for iiuid operation, a bore extending longitudinally of saidhousing, end pieces attached at each end of said housing formingoperating chambers at each end of said housing, diaphragms in each ofsaid chambers dividing the same into pumping chambers and actuatingchambers, a wall centrally of said bore dividing the same into alignedvalve chambers, valve members slidable in each of said valve chambers,means operably connecting each of said valve members with the diaphragmat its respective end of the housing, and passageways connecting`saidvalve chambers with said fluid inlet and outlet openings, the valvemember connected to one diaphragm being adapted to control theconnection of pressure to the other diaphragm and vice versa.

4. In a liquid fuel pump, a housing having two spaced, coaxial pumpingchambers, inlet and'outlet openings for actuating fluid, and coaxialbores between said chambers, valves in said bores, diaphragms dividingsaid chambers into actuating and pumping sides, means connecting'each ofsaid valves with a diaphragm whereby movement of a diaphragm actuatesthe valve connected therewith, and passageways formed in said housingbetween said openings and the actuating sides of said diaphragms wherebymovement of one valve by one diaphragm controls the connectionoftactuating uid to the other diaphragm and vice versa.

5. In a liquid fuel pump, a housing having two spaced, coaxial pumpingchambers, inlet and outlet openings for actuating fluid, and boresarranged on an axis parallel with the axis of said spaced chambers,diaphragms dividing said chambers into actuating and pumping sides,means connecting each of said valves with a diaphragm whereby movementof a diaphragm actuates the valve connected therewith, and passagewaysformed in said housing between said openings and the actuating sides ersaid diaphragms whereby movement of one valve by one diaphragm controlsthe connection of actuating fluid to the other diaphragm anl'vice versa.

6. In a liquid fuel pump, a housing having two spaced coaxial pumpingchambers, inlet and outlet openings for actuating fluid, and centralbore connecting said chambers, diaphragms dividing said chambers intoactuating and pumping sides, the actuating sides facing the centralbore, a sleeve in said bore having surface openings there- 1n to connectthe inlet and outlet openings of said housing with the actuating sidesof said chambers, valves in each end of said sleeve, means connectingeach of said valves with a diaphragm whereby movement of a diaphragmactuates the valve connected therewith, said` valves having surfaceopenings arranged to cooperate with the openings of said sleeve wherebythe movement of a valve connected to one diaphragm controls theconnection of actuating uid to the other diaphragm and vice versa.

` CHRISTIAAN H. BOUVY.

